/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    LeafNode.java
 *    Copyright (C) 2013 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.classifiers.trees.ht;

import java.io.Serializable;

import weka.core.Instance;

/**
 * Leaf node in a HoeffdingTree
 * 
 * @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 * @author Mark Hall (mhall{[at]}pentaho{[dot]}com)
 * @version $Revision$
 */
public class LeafNode extends HNode implements Serializable {

    /**
     * For serialization
     */
    private static final long serialVersionUID = -3359429731894384404L;

    /** The actual node for this leaf */
    public HNode m_theNode;

    /** Parent split node */
    public SplitNode m_parentNode;

    /** Parent branch leading to this node */
    public String m_parentBranch;

    /**
     * Construct an empty leaf node
     */
    public LeafNode() {
    }

    /**
     * Construct a leaf node with the given actual node, parent and parent branch
     * 
     * @param node         the actual node at this leaf
     * @param parentNode   the parent split node
     * @param parentBranch the branch leading to this node
     */
    public LeafNode(HNode node, SplitNode parentNode, String parentBranch) {
        m_theNode = node;
        m_parentNode = parentNode;
        m_parentBranch = parentBranch;
    }

    @Override
    public void updateNode(Instance inst) throws Exception {
        if (m_theNode != null) {
            m_theNode.updateDistribution(inst);
        } else {
            super.updateDistribution(inst);
        }
    }
}
